岩爆发生过程的能量判别指标

AN ENERGY CRITERION IN PROCESS OF ROCKBURST

岩爆是一种严重威胁深埋地下工程施工安全的动力灾害,但现有的可用于数值计算的岩爆判别指标都是针对静力数值计算结果提出的,仅能对岩爆发生的危险性做出静态和定性的评价,而不能合理反映实际岩爆发生的动力过程。为对岩爆进行更准确的预测,结合试验和理论分析,通过对岩爆的发生过程和机制进行深入剖析认为,对岩爆机制的研究在本质上应是对岩体中裂纹动态扩展问题的研究,并从裂纹动态扩展的角度给出岩爆的定义;在此基础上,提出一个新的岩爆能量判别指标——单位时间相对能量释放率指标,并将该指标应用于锦屏二级水电站引水隧洞岩爆案例模拟中,所得结果与实际情况基本一致,表明该岩爆判别指标可以很好地对实际岩爆的发生过程进行判别。研究成果可为深埋地下工程施工过程中的岩爆灾害评估和预测提供基本的科学依据与重要的理论支持。

Rockburst is one kind of dynamic geological disasters,which seriously threatens the safety of design and construction in deep underground engineering. However,the traditional methods for predicting rockburst can only give a qualitative assessment of rockburst proneness based on the results of static quantitative calculation. It can not reasonably reflect the occurrence process of rockburst. In order to have more accurate projections for rockburst,based on the test and theoretical analysis,an intensive study on the mechanism of rockburst is carried out thereby. In essence,the study indicates that the mechanism of rockburst should be studied based on the dynamic propagation of the crack in rock mass. Then,a definition of rockburst is given from the perspective of the dynamic propagation of the crack. Finally,based on the above,a new energy criterion of rockburst—unit time relative local energy release index(URLERI) is put forward. And it is used for numerical simulation of the rockburst case for Jinping II hydropower station. The results show that there's a general agreement between simulating results and practical. And it shows that the energy criterion of rockburst is quite reasonable. The research results offered by this paper,no matter in evaluating,forecasting and preventing of the rockburst disaster in deep underground engineering,have its own significance in theory and in application.